JavaScript That Scales
summary
A practical report on migrating a JavaScript codebase to 90% TypeScript within a year using concrete tools: a test-silent script that runs tsc and filters ignored diagnostics, temporary marker types to mark and later remove difficult type gaps, and custom .d.ts overrides. It also covers CSS .d.ts generation for class-name autocomplete and dead-CSS checking, Jest mocks typed via typeof imports, custom ESLint rules based on AST queries, and an error-count graph tracking per-directory compiler faults toward zero.
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chapters (11)
- 0:00TypeScript migration intro
- 3:16Gradual migration config
- 7:28Error handling assertions
- 10:41Type testing validation
- 12:26Typing external libs
- 15:13Custom ESLint AST rules
- 18:05Custom d.ts files
- 19:49Removing global window
- 21:57Fixing JS methods
- 22:41CSS modules typing
- 25:34Q&A
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